This is the whole problem with the law. No common sense.
If you are a felon with a BB gun and want to use it to stick up a bank, sorry, it's a weapon and you get to go up the river for life.
If you had a prior domestic and you got a BB gun to keep rabbits out of the garden, it's not.
They get too into writing it in black and white, and not enough in the situation. Unfortunately, there are too many lawyers out there who are good at making a jury think that the guy is a "good boy turning his life around" and making some bleeding heart give him yet another chance because the law is too scary.